The rapid growth of social media platforms has revolutionized marketing communications, and the recent trend of how people use social media led to the inception of the term "influencer marketing" as an increasingly popular approach for brands across markets. This development has been driven by the unparalleled increase in influencers’ presence on social media platforms, which has generated new venues for companies to connect with their desired demographic and interact with them in a more genuine and significant manner. Understanding the factors that drive the effectiveness of influencers has become increasingly important for both marketers and researchers. Numerous studies have been conducted on the topic of celebrity endorsements. However, the use of "traditional" celebrities is losing its appeal in the digital era of social media, as brands increasingly turn to social media influencers instead. Nonetheless, there is still a lack of understanding about how marketers can effectively utilize this new marketing phenomenon. This study aims to examine the role of trustworthiness, expertise, and information quality of social media influencers in shaping consumer purchase intention, with a specific focus on the mediating role of brand attitude. A total of 309 complete responses were collected via convenience sampling between January and February 2023 then the model examined by using SPSS and AMOS software. The results showed that all attributes of the influencers are affecting brand attitude as well as purchase intention, while brand attitude partially mediated the relationships. Implications, limitations and future research have also been discussed.